1. Field of the Invention
The present invention relates to medical instruments and, more particularly, to an endoscope.
2. Prior Art
U.K. Patent Application No.2130885 discloses a flexible distal end portion for an endoscope. The end portion is made from plastic material with vertebrae connected by an elongate member or spine. U.S. Pat. No.5,938,588 discloses an endoscope with wire sheaths made as solid tubes from a superelastic alloy material.
In accordance with one embodiment of the present invention, an endoscope is provided having a control section and a shaft extending from the control section. The shaft comprises an outer cover; a tubular braid member located, at least partially, inside the outer cover; and a support frame located, at least partially, inside the tubular braid member. The support frame comprises a shape memory member which is spiral shaped. The shape memory member is comprised of a superelastic shape memory alloy. A first length of the support frame comprises the shape memory member having a first width and a second length of the tubular shape comprises the shape memory member having a different second width such that the support frame has different respective stiffnesses along the first and second lengths.
In accordance with another embodiment of the present invention, an endoscope is provided having a control section and a shaft extending from the control section. The shaft comprises a front end member; a rear end member; a support frame connecting the front end member to the rear end member; and a tubular braid member surrounding the support frame. The tubular braid member is comprised of interwoven thread members comprised of superelastic shape memory alloy. The tubular braid member is heat treated to memorize home shapes of the thread members and the tubular braid member is then subsequently elongated and fixedly attached to the front and rear members with the thread members being elastically deformed towards a straightened shape.
In accordance with one method of the present invention, a method of manufacturing an endoscope shaft is provided comprising steps of providing a member comprised of superelastic shape memory alloy; forming the member into a support frame having a general spiral shape, wherein a first length of the support frame has spiral sections which each have a first width measured along an axis of the spiral shape and a second length of the member has spiral sections which each have a second different width measured along the axis of the spiral shape; connecting the support frame to a front end member and a rear end member; and connecting a Lubular shaped braid member to the first and second members over the support frame.